The swine flu virus first detected in Mexico can no longer be contained and countries should focus on mitigating its effects, a top UN official said.
UN food inspectors are going to Mexico to examine reports that industrial pig farms were the source of the outbreak.
The number of probable deaths from the virus there has risen to 152.
New Zealand confirmed at least three cases on Tuesday, and Israel one.
The US, Canada, Spain and Britain confirmed cases earlier but no deaths have been reported outside Mexico.
WHO PANDEMIC ALERT PHASES
- Phase 1: No viruses circulating among animals causing infections in humans
- Phase 2: Animal influenza virus causes infection in humans, and is considered potential pandemic threat
- Phase 3: Influenza causes sporadic cases in people, but no significant human-to-human transmission
- Phase 4: Verified human-to-human transmission able to cause community-level outbreaks. Significant increase in risk of a pandemic
- Phase 5: Human-to-human transmission in at least two countries. Strong signal pandemic imminent
- Phase 6: Virus spreads to another country in a different region. Global pandemic under way